U.S. patent application number 11/192912 was filed with the patent office on 2007-02-01 for optical system architecture.
Invention is credited to Anurag Gupta, Scott Lerner, Arthur Piehl.
Application Number | 20070024811 11/192912 |
Document ID | / |
Family ID | 37693910 |
Filed Date | 2007-02-01 |
United States Patent
Application |
20070024811 |
Kind Code |
A1 |
Piehl; Arthur ; et
al. |
February 1, 2007 |
Optical system architecture
Abstract
A projection system is disclosed that has a
chromaticity/luminosity module in serial optical communication with
a luminosity module. The chromaticity/luminosity module has a pair
of chromaticity/luminosity modulators configured to modulate
incident light to generate color on a pixel-by-pixel basis. The
luminosity module has a pair of luminosity modulators configured to
modulate incident light to generate a light image.
Inventors: |
Piehl; Arthur; (Corvalllis,
OR) ; Gupta; Anurag; (Corvallis, OR) ; Lerner;
Scott; (Corvallis, OR) |
Correspondence
Address: |
HEWLETT PACKARD COMPANY
P O BOX 272400, 3404 E. HARMONY ROAD
INTELLECTUAL PROPERTY ADMINISTRATION
FORT COLLINS
CO
80527-2400
US
|
Family ID: |
37693910 |
Appl. No.: |
11/192912 |
Filed: |
July 29, 2005 |
Current U.S.
Class: |
353/30 ;
348/E9.027 |
Current CPC
Class: |
H04N 9/3126 20130101;
G03B 21/005 20130101; G03B 21/26 20130101; H04N 9/3111 20130101;
H04N 9/3167 20130101; G02B 27/1026 20130101; H04N 9/3102 20130101;
G02B 27/141 20130101; G03B 33/08 20130101; H04N 9/3188 20130101;
G03B 33/14 20130101 |
Class at
Publication: |
353/030 |
International
Class: |
G03B 21/26 20060101
G03B021/26 |
Claims
1. A projector system, comprising: a chromaticity/luminosity module
having a pair of chromaticity/luminosity modulators configured to
modulate incident light to generate color on a pixel-by-pixel
basis; and a luminosity module having a pair of luminosity
modulators configured to modulate incident light to generate a
light image, said luminosity module being in serial optical
communication with said chromaticity/luminosity module.
2. The system of claim 1, wherein said chromaticity/luminosity
module receives white light from a light source and projects
colored light to said luminosity module.
3. The system of claim 1, wherein said luminosity module receives
white light from a light source and projects a grayscale light
image to said chromaticity/luminosity module.
4. The system of claim 1, wherein said chromaticity/luminosity
modulators are non-polarizing.
5. The system of claim 4, wherein said pair of
chromaticity/luminosity modulators each include a pixelated,
variable absorption backplane.
6. The system of claim 5, wherein said pair of
chromaticity/luminosity modulators further include individual
pixels having a top reflector and a bottom reflector separated by a
variable distance that defines an optical cavity therebetween.
7. The system of claim 6, wherein said variable distance is
adjustable in response to an image source signal to reflect light
having a desired wavelength from said chromaticity/luminosity
modulator.
8. The system of claim 1, wherein said pair of luminosity
modulators comprise liquid crystal on silicon (LCOS)
microdisplays.
9. The system of claim 1, wherein said luminosity modulators
comprise non-polarizing spacial light modulators, and wherein said
luminosity module further includes a pair of quarter-wave phase
retarders positioned in front of said non-polarizing spacial light
modulators.
10. The system of claim 1, wherein said pair of
chromaticity/luminosity modulators are each configured to modulate
light of a different range of wavelengths.
11. The system of claim 1, wherein said chromaticity/luminosity
module further includes a dichroic beam splitter to divide
impending light into a plurality of groups based upon the
wavelengths of the light.
12. The system of claim 1, wherein said pair of luminosity
modulators are each configured to modulate light of a different
polarization.
13. The system of claim 1, wherein said luminosity module further
includes a polarizing beam splitter configured to divide impending
light into a plurality of polarization states.
14. The system of claim 1, further including a relay lens group
disposed between said chromaticity/luminosity module and said
luminosity module, and being configured to both direct light to and
project light from at least one of said chromaticity/luminosity
module and said luminosity module.
15. The system of claim 1, further including a reflecting surface
configured to direct light from a light source to one of said
chromaticity/luminosity module and said luminosity module, said
reflecting surface being substantially aligned with a pupil plane
between said chromaticity/luminosity module and said luminosity
module.
16. The system of claim 1, further including a polarizer positioned
upstream of said luminosity module.
17. The system of claim 1, wherein said luminosity modulators are
offset relative to each other such that overlapping pixels of said
luminosity modulators generate sub-pixels.
18. The system of claim 17, wherein said luminosity modulators are
offset relative to each other approximately one half of a pixel in
both an X direction and a Y direction.
19. A method for projecting an image, comprising the steps of:
receiving and modulating incident light at a
chromaticity/luminosity module, said chromaticity/luminosity module
including a pair of chromaticity/luminosity modulators, to generate
desired colors on a pixel by pixel basis; and receiving and
modulating incident light at a luminosity module, said luminosity
module including a pair of luminosity modulators, to generate a
desired light image.
20. The method of claim 19, wherein said incident light at said
chromaticity/luminosity module is white light, and said
chromaticity/luminosity module optically communicates colored light
to said luminosity module.
21. The method of claim 19, wherein said incident light at said
luminosity module is white light, and said luminosity module
optically communicates a grayscale light image to said
chromaticity/luminosity module.
22. The method of claim 19, further comprising the step of
directing incident light to and projecting modulated light from at
least one of said chromaticity/luminosity module and said
luminosity module using a single relay lens group.
23. The method of claim 19, wherein said step of receiving and
modulating incident light at said chromaticity/luminosity module
comprises dividing said incident light into a plurality of groups
based upon wavelength and directing each said group to a respective
chromaticity/luminosity module.
24. The method of claim 23, wherein said step of receiving and
modulating incident light at said chromaticity/luminosity module
further comprises recombining said groups of light after they have
been modulated by said respective modulator.
25. The method of claim 19, wherein said step of receiving and
modulating incident light at said luminosity module comprises
dividing said incident light into a plurality of polarization
states and directing light of each said polarization state to a
respective luminosity modulator.
26. The method of claim 25, wherein said step of receiving and
modulating incident light at said luminosity module comprises
recombining said light of different polarization states after said
polarized light has been modulated by said respective
modulator.
27. The method of claim 19, wherein said luminosity modulators are
offset relative to each other, and said luminosity modulators
thereby generate subpixels.
28. A projector system, comprising: a first means for modulating
incident light and a second means for modulating incident light,
said first and second means for modulating incident light being
configured to collectively generate color on a pixel-by-pixel
basis; and a third means for modulating incident light and a fourth
means for modulating incident light, said third and fourth means
for modulating light being configured to collectively generate a
light image; wherein said first and second means for modulating
incident light are in optical communication with said third and
fourth means for modulating light.
Description
BACKGROUND
[0001] Image projection devices are widely used today in many
electronic applications, such as televisions, computers, and
projectors. These projection devices may employ any of several
relatively new types of luminosity modulators, such as Digital
Light Processing ("DLP"), Liquid Crystal Display ("LCD"), and
Liquid Crystal on Silicon ("LCOS") microdisplays to project an
image onto a viewing medium, such as a television viewing panel,
screen, wall, etc.
[0002] While each of these different types of luminosity modulators
improves overall brightness, contrast, and resolution over prior
vacuum tube, transistor, and slide projector technology, each has
its own distinct drawbacks that affect the image produced on the
screen. For example, a DLP microdisplay typically provides images
in black and white and cooperates with hardware such as chromatic
modulators in the form of color wheels to produce a spectrum of
colors. However, color wheels generally pass only a single color at
any given time (effectively reducing the amount of light projection
by the system) and DLPs may exhibit a lower resolution than its LCD
and LCOS counterparts because of the larger pixel sizes DLPs
employ.
[0003] The luminosity modulators that are polarization based, such
as the LCD and LCOS modulators, require the prepolarization of
light to achieve some contrast between the images displayed on the
screen. Prepolarization, however, generally results in the loss of
about half of the light produced by a light source for image
projection. Polarization recovery systems may be added to the
projection system, at an added cost, to recover much of the lost
light. Even with the polarization recovery systems, these
modulators still exhibit a relatively low contrast, which affects
theater or low ambient light viewing. Also, for these modulators to
modulate color, three separate modulators are used--one for the
projection of each of the colors of red, blue, and green--or the
use of sequential color which requires added hardware and a further
reduction in efficiency.
[0004] Optical lenses are employed with the luminosity modulators
to concentrate the light transmitted to and reflected from the
particular luminosity modulators. Typically, one set of optical
lenses, "illumination lenses," transmits the light to the
luminosity modulators and a second set of optical lenses,
"projection lenses," receives the reflected light from the
luminosity modulators and projects the image on to a viewing
medium. The use of multiple sets of lenses to separately accomplish
illumination and projection adds significant complexity to the
design of a projector or television as well as added costs to the
overall system.
[0005] The embodiments described hereinafter were developed in
light of this situation and the drawbacks associated with existing
systems.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] The present embodiments will now be described, by way of
example, with reference to the accompanying drawings, in which:
[0007] FIG. 1 is an optical schematic diagram of a projection
system according to an exemplary embodiment;
[0008] FIG. 2 is a flow diagram showing the steps in the projection
of an image by the projection system of FIG. 1;
[0009] FIG. 3 is an optical schematic of a projection system
according to an alternative embodiment;
[0010] FIG. 4 is an optical schematic of a projection system
according to a third embodiment;
[0011] FIG. 5 is an optical schematic of a projection system
according to a fourth embodiment; and
[0012] FIGS. 6a-6b illustrate high resolution sub-pixels formed by
offsetting the luminosity modulators illustrated in other
embodiments of the projection system shown in FIGS. 1, 3, 4 and
5.
DETAILED DESCRIPTION
[0013] A system for projecting a light image onto a viewing surface
is described herein. The system includes a luminosity module and a
chromaticity/luminosity module in serial optical communication with
each other to generate a colored light image that is projected to a
viewing surface, such as a screen, wall, etc. The luminosity module
modulates light intensity to generate a light image. The
chromaticity/luminosity module modulates light to provide color to
the light image. The system also includes at least one relay lens
group that functions both to direct white light to one or the other
of the modules, where the white light is modulated, and also to
direct the modulated light to the other of the modules. The
projection system described herein can be employed in a variety of
different environments, including televisions, monitors,
projectors, and a variety of other systems involving the generation
and projection of light images.
[0014] FIG. 1 illustrates an exemplary embodiment of the projection
system. The exemplary projection system 10 includes a light source
16, a reflecting surface 28, a chromaticity/luminosity module 11, a
first relay lens group 18, a second relay lens group 20, a
luminosity module 13, and a projection lens 30. In general, white
light generated by the light source 16 is reflected and directed to
the chromaticity/luminosity module 11 by reflecting surface 28
through first relay lens group 18. The chromaticity/luminosity
module 11 modulates the white light in response to image source
signals from a controller (not shown) to provide a desired color
distribution for the light image. The colored light is reflected
from the chromaticity/luminosity module 11 back through first relay
lens group 18 and through second relay lens group 20 to the
luminosity module 13. The luminosity module 13 modulates the
intensity of the colored light in response to image source signals
from a controller (not shown) to generate a colored light image.
The colored light image is reflected from the luminosity module
through the projection lens 30 to the viewing surface. The pupil
plane 22 exists somewhere between the first relay lens group 18 and
the second relay lens group 20. In some embodiments, the reflecting
surface 28 is aligned with the pupil plane 22 (as shown in FIG. 1),
which is beneficial to achieve the smallest size of the reflector
28. At pupil plane the beam bundle is the smallest. The chances of
unintended mechanical interference between the reflector 28 and the
beam bundles are greatly reduced. The first and second relay lens
groups 18 and 20 are shown as each having a particular number of
lenses. A person skilled in the art will recognize that the first
and second relay lens groups 18 and 20 may have a variety of
different number and configurations of lenses to make up the
respective lens groups 18 and 20. Further, a variety of
differently-configured projection lenses 30 can be used in
connection with the disclosed projection system 10. The light
source 16 may be, for example, an illumination relay. A person
skilled in the art will further recognize that additional or
replacement components could be incorporated into the system
10.
[0015] Chromaticity/luminosity module 11 includes a pair of
chromaticity/luminosity modulators 12a and 12b and a dichroic beam
splitter 26. Chromaticity/luminosity modulators 12a and 12b may
include one or more pixelated, variable absorption backplanes, and
other devices that can operate to modulate both light and color.
The term "pixelated", used in conjunction with
chromaticity/luminosity modulators herein, refers to a spatial
light modulator, such as a chromaticity/luminosity modulator that
has independently-controlled pixels so as to be able to spatially
modulate light intensity/color. The chromaticity/luminosity
modulators, 12a, 12b illustrated in FIG. 1 may be provided in a
number of ways. For example, the variable absorption backplane may
include an array of pixels where each pixel is composed of a top
reflector and a bottom reflector separated by a distance T that
defines an optical cavity therebetween. The optical cavity may
utilize optical interference to reflect a wavelength band of
electromagnetic radiation, including visible light. The intensity
of the reflected wavelength band (e.g. red light) may be controlled
by rapidly modulating the thickness of the optical cavity between
substantial absorption and substantial reflection of the wavelength
band. The wavelength band (e.g. red light) and/or the intensity may
be selected in correspondence with one or more pixels of a display
image, perhaps provided by an image source signal from a controller
(not shown). In the embodiment illustrated in FIG. 1,
chromaticity/luminosity modulators 12a, 12b do not require the
prepolarization of light and may be positioned in an "off-axis"
dichroic configuration. "Off-axis" means that the light incident to
chromaticity/luminosity modulators 12a, 12b is not on the same axis
as the actual modulators 12a, 12b themselves. The use of "off-axis"
light also allows for the use of the first relay lens group 18 to
be used simultaneously to both illuminate the
chromaticity/luminosity modulators 12a, 12b and to project light
from the chromaticity/luminosity modulators 12a, 12b, thereby
providing increased flexibility to the design of the projection
system.
[0016] In operation, white light enters the luminosity module 11
from first relay lens group 18. The dichroic beam splitter 26
divides the white light based upon wavelength, i.e., color, and
correspondingly directs the divided light to the
chromaticity/luminosity modulators 12a and 12b.
Chromaticity/luminosity modulators 12a and 12b may be functionally
divided in several ways, such as between one pixelated, variable
absorption backplane 12a for modulating blue/green light, and one
pixelated, variable absorption backplane 12b for modulating red
light. That is, the white light may be divided such that red light
is directed to one chromaticity/luminosity modulator 12a and
blue/green light is directed to the other chromaticity/luminosity
modulator 12b. The chromaticity/luminosity modulators 12a and 12b
modulate the respective incident light, which is recombined by the
dichroic beam splitter 26 and is reflected from the
chromaticity/luminosity module 11 back through the first relay lens
group 18 and through the second relay lens group 20. Each frame of
light that exits the chromaticity/luminosity modulator 11 has been
modulated such that each pixel of the frame is of the desired color
for that pixel, according to the desired image ultimately to be
displayed on the display surface.
[0017] Luminosity module 13 includes a pair of luminosity
modulators 14a, 14b and a polarizing beam splitter (PBS) 24. In the
embodiment illustrated in FIG. 1, luminosity modulators 14a, 14b
are liquid crystal on silicon ("LCoS") microdisplays. LCOS
microdisplays typically combine the liquid crystals employed in
liquid crystal displays ("Lids"), a transmissive technology, with a
reflective mirror (silicon) substrate. Each liquid crystal cell
represents a single pixel in the LCOS technology. As light is
projected onto the LCoS, it passes through each liquid crystal and
is reflected by the mirror below. As the liquid crystal cells are
electrically activated, as determined by the image to project, the
light polarization state reflected from the cell is modulated. The
liquid crystal cells may also be partially activated to modulate
the polarization state to varying degrees. In FIG. 1, the
polarizing beamsplitter 24 is the only polarization component used,
and it acts as both the input polarizer for incoming light to
luminosity modulators 14a, 14b and as an analyzer for the light
being directed toward projection lens 30.
[0018] In operation, the colored light that illuminates the
luminosity module 13 (from chromaticity/luminosity module 11) is
split into two different polarizations, i.e., a P polarization and
an S polarization, by the PBS 24. The P polarization light is
directed to one of the luminosity modulators, e.g., 14a, and the S
polarization light is directed to the other of the luminosity
modulators, e.g., 14b. The luminosity modulators 14a, 14b modulate
the impending polarized light in response to image source signals
from a controller (not shown). The image source signals generally
represent a desired light image to generate. The modulated
polarized light from each of the luminosity modulators 14a, 14b is
converted into modulated intensity by a polarizing "analyzer,"
which in this case is the PBS 24 that originally split the incoming
light into two polarization states. In this way, the two luminosity
modulators 14a, 14b operate in an optically parallel configuration.
As such, luminosity modulators 14a, 14b can play equal roles as
luminosity modulators and can be driven by the same voltages. The
described operation modulates the colored light and projects an
image. A single LCOS microdisplay may be employed to simply
modulate light.
[0019] FIG. 2 illustrates in more detail an exemplary set of steps
used in operation of the complete projection system 10 shown in
FIG. 1. At step 100, white light is provided to
chromaticity/luminosity module 11 through relay lens group 18. At
step 110, that white light is split into a plurality of color
(frequency) groupings using dichroic beam splitter 26. At step 120,
the color groupings are directed to respective
chromaticity/luminosity modulators 12a, 12b, which modulate the
light to generate color for the image to be projected by the
system. At step 130, the modulated light is recombined by the
dichroic beamsplitter 140. The combined light is projected to the
luminosity module 13 by relay lens group 18 at step 140. At step
150, that light is split into polarization states P and S by
polarizing beam splitter 24. At step 160, the polarized light is
directed to respective luminosity modulators 14a, 14b, which
modulate the impending light to generate the light image to be
projected to the viewing surface. At step 170, the modulated light
is recombined by the polarizing beam splitter 24. Finally, at step
180, the colored light image is projected onto the viewing
surface.
[0020] The projection system 10 described in connection with FIGS.
1 and 2 have several benefits over known systems. LCOS
microdisplays are known in the art for producing images with very
high resolution and sharpness. The image produced by LCoS
microdisplays also tends to look "smoother" than an image produced
by a digital light processing ("DLP") microdisplay. However, LCOS
microdisplays typically have a relatively low contrast and require
multiple LCOS microdisplays to produce color. Optically coupling
LCOS microdisplays (e.g. elements 14a and 14b) with the
chromaticity/luminosity modulators 12a, 12b improves the contrast
of the projected light image and eliminates the requirement for
multiple LCOS microdisplays to generate color.
[0021] Because the chromaticity/luminosity module 11 produces
intrinsic color modulation functionality, there is flexibility in
the way that color is managed in any given display system
embodiment. As an example, in the case of a display system
embodiment that utilizes a single variable absorption backplane,
the variable absorption backplane may, (1) operate to produce a
color filled sequential mode (e.g. RGB subframes displayed
sequentially) directly at the variable absorption backplane,
without requiring an upstream colorwheel or color switching device,
or (2) operate to produce a full-color mode directly at the
variable absorption backplane by independently controlling the
optical path length within each pixel. Other display system
embodiments and color management modes are also possible.
[0022] Positioning luminosity module 13 and chromaticity/luminosity
module 11 in series, as shown in FIG. 1, permits the total
available contrast to become approximately the product of the
individual contrasts (noting the projector optics may limit the
total contrast achieved). Because the potential available contrast
is so high, tolerances required for optics that manage polarization
in the system may be significantly relaxed compared to the
tolerances required in designs that only employ a luminosity
modulator. Also, configuring a pair of luminosity modulators such
that they modulate the P and S states in parallel allows both light
polarization states to be utilized rather than losing as much as
half the light intensity with a single luminosity modulator.
Because two luminosity modulators 14a and 14b are employed in this
particular embodiment, inefficient polarization recovery systems do
not have to be employed with projection system 10. Luminosity
modulators 14a, 14b provide the improved brightness and resolution
of an image while chromaticity/luminosity modulators 12a, 12b
provide the improve contrast and color to further enhance the
projected image versus other light and color modulating
technologies.
[0023] Several variations of the embodiment of the projection
system described in connection with FIG. 1 are possible. For
example, as shown in FIG. 3, the system may employ all of the same
components as described in FIG. 1, but the "order" of the
chromaticity/luminosity module 11 and the luminosity module 13 may
be reversed. That is, white light from a light source 16 may be
modulated by a luminosity module 13 to generate a gray scale light
image first, and the light image can modulated by a
chromaticity/luminosity module 11 to add color to the light image
second. Reversing the order of the chromaticity/luminosity module
11 and the luminosity module 13 may improve the thermal performance
of the system.
[0024] Further, in some embodiments that do not make full use of
the capabilities of the first relay lens group 18, the first relay
lens group 18 may be omitted from the system, which has the benefit
of minimizing contrast loss due to stray reflections off of the
lens group 20.
[0025] FIG. 4 illustrates yet another embodiment of the projection
system 10, wherein a polarizer 34, such as a wire grid, stacked
plate polarizer, or polarization recovery system is disposed
upstream of the luminosity module 13, and particularly the
polarizing beamsplitter 24 to provide multiple operating modes. The
polarizer 34 will restrict the light in the P-state without
appreciably attenuating the S-state, which may cut illumination
brightness in half, but increases the contrast. Contrast is
increased because the primary loss of contrast is the P-state
leakage that occurs in the PBS 24 and the fact that the luminosity
modulators 14a, 14b are polarization modulators. Only a partial
attenuation of the P-state polarization is required to
significantly increase contrast. For example, a 50% reduction of
the P-state yields a 100% increase in contrast, with only a 25%
overall loss in brightness. With the increased contrast, projection
system 10 may be used in a theater mode. In this manner, projection
system 10 may be used both in a presentation mode, requiring higher
brightness, and a theater mode, requiring higher contrast, thereby
increasing the flexibility of the projection system.
[0026] Another embodiment of the projection system 10 is
illustrated in FIG. 5. In this embodiment, luminosity modulators
14a, 14b may be non-polarization based luminosity/chromaticity
modulators, such as a pixelated, variable absorption backplane. If
non-polarization based luminosity/chromaticity modulators are used,
then quarter-wave phase retarders 15a, 15b may be used in front of
the luminosity/chromaticity modulators 14a, 14b to allow
recombination of the images from the two modulators. The luminosity
module still uses polarization to direct the S-state to one
modulator, and the P-state to the other modulator, but the contrast
of the module is not now limited by the P-state leakage of the PBS.
When PBSs are used with polarization based modulators, such as LCOS
modulators, the contrast is limited by the P-state leakage of the
PBS. When PBSs are used with variable absorption backplanes and
quarter wave plates, the P-state leakage only reduces the light
output to the projection lens, but not the contrast. The above
embodiment could use sequential color, for example by using
colorwheels or LEDs, to provide the chromaticity modulation, and
the luminosity modulator could provide the spacial luminosity
modulation. Because this configuration uses both the S and P
states, it allows high efficiency, on-axis, optical operation
without the usual limitations associated with polarization based
systems, such as low contrast due to P-state leakage and the need
for polarization recovery systems.
[0027] The parallel arrangement of two luminosity modulators 14a,
14b, as is illustrated in the above-described embodiments, enables
yet another embodiment that can significantly increase system
resolution. Specifically, the luminosity modulators 14a, 14b can be
offset from each other by approximately 1/2 pixel, creating
approximately four sub-pixels for each of the original pixels,
thereby increasing the resolution of the system. By shifting one of
the luminosity modulators approximately 1/2 pixel with respect to
the other luminosity modulator in the X and Y directions, the
resolution of the system can be essentially doubled. This is shown
in FIGS. 6a, 6b, and 6c. FIGS. 6a and 6b each show a single
luminosity modulator, one with light pixels 50 and the other with
dark pixels 50. FIG. 6c shows the luminosity modulators of FIGS. 6a
and 6b combined in a luminosity modulator and offset by
approximately 1/2 pixel relative to each other to create sub-pixels
52. The brightness of each sub-pixel 52 is the sum of the
brightness of the pixels 50 that overlap to create the sub-pixel
52. If the sub-pixel brightness is generated by interpolating the
original source data, resolution exceeding the original source data
can be realized. Because the human eye primarily perceives
resolution as coming from luminosity, the lower resolution of the
chromaticity component should not significantly affect the
perceived resolution. By shifting one modulator with respect to the
other, the visibility of the non-active interpixel area is also
minimized. This reduces the so called "screen door" effect. This
method of increasing resolution is referred to as
"static-wobulation" to differentiate it from the method of
increasing resolution known as wobulation, where a projected image
is shifted temporally using vibrating mirrors or lenses.
Static-wobulation does not require the addition of the above
luminosity/chromaticity spacial light modulator module to be
useful. If the chromaticity of the illumination is modulated in a
sequential color fashion, for example by using colorwheels or LEDs,
the static-wobulated spacial luminosity module can be the only
spacial light modulator required.
[0028] While the present invention has been particularly shown and
described with reference to the foregoing preferred embodiment, it
should be understood by those skilled in the art that various
alternatives to the embodiments of the invention described herein
may be employed in practicing the invention without departing from
the spirit and scope of the invention as defined in the following
claims. It is intended that the following claims define the scope
of the invention and that the method and apparatus within the scope
of these claims and their equivalents be covered thereby. This
description of the invention should be understood to include all
novel and non-obvious combinations of elements described herein,
and claims may be presented in this or a later application to any
novel and non-obvious combination of these elements. The foregoing
embodiment is illustrative, and no single feature or element is
essential to all possible combinations that may be claimed in this
or a later application. Where the claims recite "a" or "a first"
element of the equivalent thereof, such claims should be understood
to include incorporation of one or more such elements, neither
requiring nor excluding two or more such elements.
* * * * *